Description: (Applicant's Description) The Protein Microchemistry Core assists cancer researchers with all aspects relating to the isolation, purification, identification and production of peptides and proteins. Forty Cancer Center investigators from 9 of the 10 Cancer Programs have utilized the Protein Microchemistry Core since 1996. In 1999, the Protein Microchemistry Core facilities at UCHSC and the National Jewish Center were combined. The combination of these Cores resulted in the doubling of the use of microsequencing facilities over 1998 values and tripled the use of mass spectrometry services. Restructuring of the Core also added peptide synthesis as a new Core service. This service already has a significant usage rate and demand appears to be increasing. Increased use of the Core by investigators interested problems of protein structure and analysis of complex protein mixtures led to its reorganization and expansion. The expanded version of the Protein Microchemistry Core is significantly enhanced through the addition of state-of-the-art mass spectrometry, an upgrade in Edman sequencing hardware and the addition of peptide synthesis. Several mass spectrometers, including 3 electrospray ionization (ESI) systems and a matrix-assisted laser desorption ionization (MALDI) mass spectrometer combined with a Perkin Elmer Procise 494 Edman sequencer will ensure that researchers have access to the most powerful hardware currently available. The core also provides the expertise, technical resources and collaborative interactions to ensure that these instruments are optimally employed in solving the problems of the user base. The Protein Microchemistry Core, directed by Mark Duncan Ph.D., is composed of two facilities: the Proteomics Unit and the Protein Structure Unit. The Core occupies space on the University of Colorado Health Sciences Center (UCHSC) campus, and at National Jewish Center (NJC). The Core has access to all the necessary equipment to realize its objectives, but the hiring of some additional staff is necessary.